The present invention relates to print controlling apparatuses and a print controlling method. More particularly, it relates to a print controlling apparatus and a print controlling method which utilize a multiprocessor in order to rapidly operate any of page printers and shuttle printers such as laser printers, LED (light emitting diode) printers and LCS (liquid-crystal shutter) printers.
In each of the print controlling apparatuses proposed by the inventors before as disclosed in Japanese Patent Applications No. 158481/1988 and No. 282747/1989, the reception of a chain of print commands from a host computer, the drawing of characters etc. into page buffers, and prints for the page buffers having completed the drawing are concurrently processed, whereby the print throughput of a printer is raised-up to the highest performance thereof. The highest performance of the printer is accomplished on condition that a drawing time period per page does not substantially exceed the print time period of a printer mechanism per page (the shortest print time period for one page).
In a print controlling apparatus disclosed ,in Japanese Patent Application Laid-open No. 263055/1989, each page is divided into a plurality of areas, drawing processors dedicated to the respective areas are prepared, and the respective processors draw the corresponding areas independently of one another, thereby intending to attain an enhanced drawing performance and to heighten the speed of the print of one page. With this apparatus, even when a drawing time period per page exceeds the print time period of a printer mechanism per page, the print performance of a printer can be enhanced for the print of only one page (the first print).
In a print controlling apparatus disclosed in Japanese Patent Application Laid-open No. 263051/1989, each page is divided into a plurality of areas, either of a character drawing processor and a pattern drawing processor is assigned to each of the areas, and the respective processors draw the areas independently of one another, thereby intending to attain an enhanced drawing performance and to heighten the speed of the print of one page.
Besides, prior-art techniques each employing a plurality of processors for a print control are disclosed in the official gazettes of Japanese Patent Applications Laid-open No. 63852/1990 and No. 108567/1990.
The above apparatuses in Japanese Patent Applications No. 158481/1988 and No. 282747/1989 have the problem that, when the drawing time period per page is substantially in excess of the print time period of the printer mechanism per page, the print throughput of the printer bercomes lower than the highest performance thereof.
With the apparatuses in Japanese Patent-Applications Laid open No. 263055/1989 and No. 263051/1989, the drawing performance for only one page is high. Since, however, either of the apparatuses does not concurrently process the drawing and the print, it has the problem that the highest performance of the printer is not attained in case of consecutively printing a plurality of pages which constitute a document and which have different print contents, respectively (hereinafter, simply termed the "consecutive print mode").
Moreover, with the apparatus in Japanese Patent Application Laid-open No. 263051/1989, in a case where each page contains only characters or only patterns, the pattern drawing processor or character drawing processor corresponding thereto is useless. This leads to the problem that the drawing performance cannot be enhanced, so even the print of one page cannot be satisfactorily heightened in speed.
Further, any of the prior-art techniques each utilizing the plurality of processors does not take it into account at all that the plurality of processors in parallel draw the different pages in the consecutive print mode.